. 2021 Sep 17;100(12):101490. doi: 10.1016/j.psj.2021.101490

Table 7.

Occurrence of White Striping (WS) (%) in the breast meat of broiler chickens fed with diets containing different vitamin A supplementation.

		Vitamin A (IU/Kg)
	Supplementation¹	0	6,000	16,000	26,000	36,000	46,000	Average²	SEM	P (Anova)	P (Test F)	P (Regression)
Normal	T – 21	11.25	53.36	56.25	46.02	55.97	50.48	45.56	3.377	0.0017	0.0045	0.0026 (Q)
Normal	T – 42	35.71	35.71	37.09	34.96	33.31	34.48	35.21	2.396	0.9989	0.0045	0.9368
Light	T – 21	21.25	32.32	30.36	40.45	30.56	35.92	31.64	2.081	0.5411	0.0347	0.5411
Light	T – 42	39.29	39.39	28.78	42.38	42.38	46.67	39.48	2.133	0.2396	0.0347	0.2396
Moderate	T – 21	41.25	8.17	10.71	10.85	8.04	10.03	14.84	2.396	0.0002	0.7899	0.0011(Q)
Moderate	T – 42	16.96	20.53	26.99	14.50	15.32	17.10	18.57	1.576	0.2100	0.7899	0.2072
Severe	T – 21	26.25	7.14	2.68	2.68	5.43	3.57	7.96	1.591	0.0001	0.4681	<0.0001(Q)
Severe	T – 42	8.04	5.36	7.14	8.17	8.99	2.75	6.74	1.214	0.0181	0.4681	0.7152

L, linear; Q, Quadratic.

WS normal (T-21d): - 0.0000000402676 vit A² + 0.00236 vit A + 23.,81484; R²: 0.27; Vit. A for maximum response: 29,301 IU/ kg; Maximum response: 58.39. WS moderate (T-21 d): 0.00000000295402 vit A² - 0.00177 vit A + 31.71040; R²: 0.32; Vit. A for minimum response: 29,959 IU/kg; Minimum response: 5.20. WS severe (T-21d): 0.000000002330068 vit A² - 0.00139 vit A + 21.07060; R²: 0.44; Vit. A for minimum response: 29,827 IU/kg; Minimum response: 0.3405.

T-21 d: birds supplemented with treatments in the period of the 4 to 21 days of age; T-42 d: birds supplemented with treatments in the period of the 4 to 42 days of age.

Test F (P ≤ 0.05) for comparing the averages of vitamin A supplementation times.